An access point (AP) transmits/receives wireless client traffic to/from wireless clients in a wireless network over wireless channels defined in a frequency allocation spectrum. The spectrum allocates Dynamic Frequency Selection (DFS) channels and Terminal Doppler Weather Radar (TDWR) channels in a 5 GHz band to primary users having priority over wireless client traffic in the allocated channels. Therefore, before the AP can use any DFS or TDWR channel, the AP searches/pre-scans for a primary user on that channel. If the channel is found to be free of a primary user, the AP may then use the channel.